TWI660983B - Development of material for cyclopentadiene polyfluorene gas separation membrane - Google Patents

Abstract

The invention provides a polynonimine containing a five-carbon ring side chain and a preparation method thereof, the polycarbonitrile having a five-carbon ring side chain having the following structure: Wherein, the Ar system is selected from and One of the groups formed; n is a positive integer of 70-140.

Thereby, the pentacyclic ring compound derived from dicyclopentadiene (DCPD) is introduced into the polyamidiene material, and the five-carbon side ring is used to prevent the intermolecular stacking, and the free volume of the polymer is increased to serve as a gas separation membrane. Application.

Description

Development of material for cyclopentadiene polyfluorene gas separation membrane

The invention relates to the development of a material for the separation of polyimine gas, in particular to the development of a material containing a cyclopentadiene polyimine gas separation membrane.

The gas separation membrane has the ability to separate one or more gases, can be used to recover hydrogen or concentrate carbon dioxide in an industrial environment, and can also separate products in the laboratory. The gas separation membrane is usually composed of a polymer, and a polymer having micropores is designed through a molecular structure to change the free volume between the polymers (Polymer of Intrinsic Microporosity, as shown in US Pat. No. 8,098,486 B2 or the Republic of China Patent Publication No. 103107762). PIM) performs gas separation. Among them, a polyimine polymer which utilizes an asymmetric monomer structure or a large side group, in addition to preventing intermolecular stacking, improves film permeability and selectivity, and obtains a higher purity gas product. Compared with the non-twisted polyimine film, the PIM-PI film exhibits outstanding gas permeability and a large free volume between polymer chains, making it transparent or selective for gas filtration. Only certain gas molecules pass. In addition, the PIM-PI film also exhibits good chemical and thermal stability from polyimine, as well as good solubility for most organic solvents, increasing solution processing properties upon film formation.

It can be seen from the above literature that a polymethylene imine gas separation membrane having an asymmetric monomer structure or a large pendant group can enhance gas separation characteristics, and wherein a dicyclopentadiene (DCPD) is a petroleum hydrocarbon to produce ethylene. By-product, which has convenient processability, and the prepared five-carbon ring side chain can prevent the inter-molecular stacking of poly-imine, which is a promising green material. However, at present, the five-carbon ring compound derived from DCPD has not been used as a side chain to prepare a polyimine gas separation membrane.

In view of the above disadvantages of the prior art, the main object of the present invention is to provide a polyfluorene imine containing a five-carbon ring side chain and a preparation method thereof, which utilizes a petroleum hydrocarbon to produce a by-product dimer cyclopentadiene in the process of ethylene ( Dicyclopentadiene (DCPD) is used as a raw material to prepare PIM-PIs containing five-carbon side-ring diamines and various dianhydrides with a 5-carbon side ring. The five-carbon side ring is used to prevent intermolecular stacking. The free volume of the polymer is used as a gas separation membrane.

In order to achieve the above object, according to one aspect of the present invention, a polyimine having a five-carbon ring side chain having a structure of the formula (I) is provided: Wherein, the Ar system is selected from and One of the groups formed; n is a positive integer of 70-140.

In the above, the polyimine may have a molecular weight of between 55,000 and 100,000.

The present invention also provides a pentacarbon ring-containing diamine compound of the formula (A):

In the above, the compound of the formula (A) is obtained by reacting dicyclopentadiene as a raw material.

The invention also provides a preparation method of a polycarbonitrile having a five-carbon ring side chain of the formula (I), which comprises the steps of: reacting a diamine compound of the formula (A) with a mono-anhydride monomer, and performing heat treatment After the ring closure, a polyimine having a five-carbon ring side chain of the formula (I) is obtained.

In the above, the reaction molar ratio of the diamine compound (A) and the dianhydride monomer is 1:1.

In the above, the dianhydride single system is selected from the group consisting of pyromellitic dianhydride (PMDA), 4,4'-biphthalic dianhydride (BPDA) and six Fluoric dianhydride (4,4'- One of the groups consisting of (hexafluoroisopropylidene) diphthalic anhydride, 6FDA).

In the above, the solvent of the reaction may be dimethylacetamide (DMAc), dimethylformamide (DMF) or N-methylpyrrolidone (NMP); the diamine compound (A) and the dianhydride monomer The reaction solid content in the solvent is 5-40% by weight.

In the above, the reaction temperature of the diamine compound (A) and the dianhydride monomer is 20 to 40 ° C, and the reaction time is 24 to 48 hours.

In the above, the reaction temperature of the thermal ring closure reaction is 200 to 400 °C.

The present invention also provides a gas separation membrane prepared by using a polycarbonitrile having a five-carbon ring side chain of the formula (I).

In the above, the gas separation membrane is used for gas separation of carbon dioxide, oxygen, nitrogen or hydrogen, but is not limited to the gases.

The present invention provides a method of preparing a polyimine gas separation membrane. Dicyclopentadiene (DCPD) was used as a starting material, and a diamine with a five-carbon ring was prepared by isomerization reaction, alkylation reaction and substitution reaction. After the diamine and various dianhydrides are polymerized into polyimine, a side chain ring is formed to form a polymer of Intrinsic Microporosity-Polyimides (PIM-PIs), compared to the general poly The quinone imine has excellent gas permeability and selectivity.

The above summary and the following detailed description and drawings are intended to further illustrate the manner and means by which the present invention achieves its intended purpose. efficacy. Other objects and advantages of the present invention will be described in the following description and drawings.

S101-S102‧‧‧Steps

The first figure is a five-carbon ring-containing diamine compound and a five-carbon ring side chain-containing polyimine. The second figure is a preparation method of the five-carbon ring side chain-containing polyimine. The third figure is a synthesis mode of a pentacarbon cyclic diamine compound according to an embodiment of the present invention; the fourth figure is a ¹ H-NMR spectrum of a pentacarbon cyclic diamine compound according to an embodiment of the present invention; EMBODIMENT OF THE INVENTION The synthesis mode of the polyimine containing a five-carbon ring side chain; the sixth figure is the FT-IR analysis chart of the polypyridamine CPI-3 containing the five-carbon ring side chain of the embodiment of the invention; The figure is a TGA analysis diagram of a polyimine containing a five-carbon ring side chain according to an embodiment of the present invention; and the eighth figure is a DSC analysis diagram of a polyimine containing a five-carbon ring side chain according to an embodiment of the present invention; The figure is a WAXD diffraction pattern of a polyimine containing a five-carbon ring side chain and a control group according to an embodiment of the present invention.

The following is a description of the implementation of the present invention by way of specific specific examples. The person skilled in the art can easily understand the advantages and effects of the present invention by the contents disclosed in the present specification.

Please refer to the second figure for a flow chart of a method for preparing a polyimine containing a five-carbon ring side chain according to the present invention. As shown in the figure, the present invention provides a method for preparing a polyimine containing a five-carbon ring side chain, the steps comprising: reacting a diamine compound of formula (A) with a mono-anhydride monomer, and performing a thermal ring closure A polyimine having a five-carbon ring side chain of the formula (I) is obtained.

Wherein, the Ar system is selected from and One of the groups formed; n is a positive integer of 70-140.

In the above, the compound of the formula (A) is obtained by reacting dicyclopentadiene as a raw material.

The present invention also provides a gas separation membrane prepared by using a polycarbonitrile having a five-carbon ring side chain of the formula (I). Wherein, the gas separation membrane can be used The gas of carbon dioxide, oxygen, nitrogen or hydrogen is separated, but not limited to these gases.

Example:

Example 1: Please refer to the third figure, which is a synthesis mode of a five-carbon cyclic diamine compound according to an embodiment of the present invention. As shown in the figure, dicyclopentadiene (DCPD) was cleaved to obtain cyclopentadiene (CPD), and 33 g of CPD was dissolved in 100 ml of toluene, and reacted with phenol for 2 hours in the presence of phosphoric acid. The crude product was obtained. After the crude product is neutralized by adding sodium carbonate, the mixture is purified by filtration to obtain a mixture of phenol in the ortho-para-parapentenylphenol, and then separated by distillation to obtain the para-product 4-(cyclopent-2-enyl)phenol. The product was then isomerized, and after 3 g of 4-(cyclopent-2-enyl)phenol was dissolved in 30 ml of toluene, 0.15 g of catalyst PdCl ₂ (PhCN) _{2 was added} , and the reaction was carried out at a temperature of 130-150 ° C for 2 hours. reaction. After purification and recrystallization, the product 4-cyclopentenylphenol is obtained. Finally, 0.5 g of 4-cyclopentenylphenol was placed in a 50 ml double-necked round bottom flask, and 2.94 g of phenol was added as a reactant, and the reaction was completed by reacting at 80 ° C for 24 hours under 1 M hydrochloric acid. The crude product was neutralized and purified to give a dark red powdery product: 4,4'-(cyclopentane-1, 1-diyl)diphenol (CPDP).

Then, 0.5 g of CPDP was placed in a 50 mL double-necked round bottom flask, and 0.61 g of p-fluoronitrobenzene was used as a reactant, 0.815 g of potassium carbonate was used as a catalyst, and 3 ml of dimethylacetamide (DMAc) was used as a solvent. The magnet was uniformly stirred, passed through a nitrogen gas, and reacted at 150 ° C for 12 hours. After purification, the brown powder product was obtained: 1,1-bis[4-(4-nitrophenoxy)phenyl]cyclopentane (CPDNP). The chemical shifts obtained by superconducting nuclear magnetic resonance spectrometry ¹ H-NMR (δ/ppm, 400 Hz, DMSO-d ₆ ) were: 8.27 (d, 4H, Ar-H), 7.48 (d, 4H, Ar-H). , 7.14 (m, 8H, Ar-H), 2.36 (s, 4H, -CH ₂ -), 1.69 (s, 4H, -CH ₂ -).

Finally, a bisamine monomer (CPDA) was prepared, 0.5 g of CPDNP was placed, 0.04 g of a palladium/carbon catalyst was added, and the reaction was refluxed at 65 ° C for 12 hours in the presence of hydrazine. After recrystallization at room temperature, the filter cake was filtered to obtain a beige crystal product: 1,2-bis[4-(4-aminophenoxy)phenyl]cyclopentane 4,4'-(cyclopentane-1,1-diyl)diphenol ( CPDA), please refer to the fourth figure, which is a ¹ H-NMR spectrum of a pentacarbon cyclic diamine compound according to an embodiment of the present invention, and analyzed by ¹ H-NMR (δ/ppm, 400 Hz, DMSO-d ₆ ) of a superconducting nuclear magnetic resonance spectrometer. The resulting chemical shifts are: 7.23 (d, 4H, Ar-H), 6.75 (m, 8H, Ar-H), 6.59 (d, 4H, Ar-H), 4.98 (s, 4H, -NH ₂ ), 2.24 (s, 4H, -CH ₂ -), 1.62 (s, 4H, -CH ₂ -).

Example 2: Please refer to the fifth figure, which is a synthesis mode of a polyimine containing a five-carbon ring side chain according to an embodiment of the present invention. As shown in the figure, the purified dianhydride monomer was dissolved in dimethylacetamide (DMAc), and then a five-carbon cyclic diamine compound CPDA was added, and the reaction was carried out at room temperature for 24 hours at a total solid content of 15% by weight. Transparent yellowish poly-proline (PAA) solution. The PAA solution was coated and then placed in an oven, and subjected to thermal ring closure at 300 ° C to form a five-carbon ring-containing polyimide film (CPIs). In the examples of the present invention, different dianhydride monomers pyromellitic dianhydride (PMDA), 4,4'-biphthalic dianhydride (BPDA) or hexafluorocarbon are respectively used. The dianhydride (4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) reacts with the five-carbon cyclic diamine compound CPDA. The formula of the reactant species and sample name is shown in Table 1. Please refer to the sixth figure, which is an FT-IR analysis diagram of the polyimine imine CPI-3 containing a five-carbon ring side chain according to an embodiment of the present invention, and the functional group of the polyimine is analyzed by an infrared spectrometer to monitor the polymerization process. Taking CPI-3 in the sixth figure as an example, the NH asymmetric and symmetric extension absorption peaks of the diamine monomer CPDA appear at 3450 cm ^-1 and 3370 cm ^-1 , the CO extension peak appears at 1231 cm ^-1 , and the dianhydride monomer 6FDA The acid anhydride C=O stretching absorption peak appeared at 1850, 1774 cm ^-1 . The C=O asymmetry and symmetric extension absorption peak of CPI-3 after polymerization appeared at 1785 and 1719 cm ^-1 , and the CN extension absorption peak appeared at 1375 cm ^-1 , and the 6FDA C=O stretching absorption peak disappeared, which proved that the polymerization was successful. .

Since the high molecular weight polyimine is difficult to dissolve and the GPC value is measured, the molecular weight of the polymer is expressed by the inherent viscosity of the polyglycolic acid. Please refer to Table 2 for the viscosity and thermal properties of the closed-loop pre-polyamide of the five-carbon ring side chain polyimine. It can be found from Table 2 that the intrinsic viscosity η _{inh of the} synthesized polyimine is between 0.85-1.27dL/g, and the film after thermal closed-loop film formation is as shown in the sixth figure, which proves that the polymer has been successfully synthesized. The imine film has a thickness of about 30-50 μm after film formation.

Please refer to the seventh figure, which is a TGA analysis diagram of a polyimine containing a five-carbon ring side chain according to an embodiment of the present invention. As shown, the T _{d of the} CPI series _{, 5%} falls at 463-479 ° C, T _{d, 10%} falls at 489-500 ° C, there is no significant weight loss below 460 ° C, and there is still 52 at 800 ° C % or more of the char yield, showing excellent thermal stability. Please refer to the eighth figure, which is a DSC analysis diagram of a polyimine containing a five-carbon ring side chain according to an embodiment of the present invention. From the results of the differential scanning calorimeter analysis in Figure 8, the glass transition temperature (T _g ) of CPIs falls between 244 and 313 ° C, and the order of magnitude is CPI-1>CPI-2>CPI- 3, in accordance with the hardness of the dianhydride monomer (PMDA>BPDA> 6FDA), consistent with the degree of monomer hardness. This is because the rigid backbone structure limits the movement of the molecular chain and requires higher temperature energy to move the molecular chain.

Please refer to the ninth figure, which is a five carbon ring side chain according to an embodiment of the present invention. WAXD diffraction pattern of polyimine and control group. The measurement was carried out by wide-angle XRD, and it was observed whether the crystallinity disappeared and the molecular chain stacking characteristics were summarized in Table 3. In the present invention, the wide-angle X-ray of the five-carbon ring side chain polyimine and the commercially available polyimine was used in the examples of the present invention. Diffraction angle (2 θ) and molecular spacing (d-spacing). From WAXD analysis, it was found that CPI- and CPI-3, which were introduced into the five-carbon ring side chain, did not show crystallization peaks and exhibited RPI-1 compared to the control group (prepared from ODA (4,4'-Oxydianiline) and PMDA ( Pyromellitic dianhydride)) is stacked with a polymer amorphous phase of RPI-3 (prepared from ODA and 6FDA (4,4'-(hexafluoroisopropylidene) diphthalic anhydride)), which proves that the side chain ring can prevent polymer stacking and increase Intermolecular distance. Among them, CPI-3 with penta-carbon diamine and fluorine-containing dianhydride exhibited the largest polymer amorphous phase stack, so CPI-3 was selected for subsequent gas separation test.

The permeability of the gas can be measured using a pressure swing (constant volume) method. In the embodiment of the present invention, all experiments were carried out using an ultra-high purity gas. The polyimide film was first cut into a perfect circle having a diameter of 3 cm, installed in a permeation cell, and the entire apparatus was degassed. The gas to be permeated is then introduced on the upstream side, and the osmotic pressure on the downstream side is monitored using a pressure sensor. The gas permeability (P) can be determined by the following equation: P = l / (A × p) × q / t, where l is the film thickness, A is the film area, and p is the pressure difference between the upstream and downstream , q / t is the volume flow rate of gas permeation. The result of gas permeability often depends on two factors of dissolution and diffusion. In order to achieve better diffusion effect, WAXD can be used to observe the inter-molecular stacking situation, and the loose push can increase the gas diffusion ability. According to WAXD analysis, the pore characteristics of CPI-3 are the largest among CPIs. Therefore, CPI-3 was selected for further gas separation test. The results are shown in Table 4, which is a five-carbon ring side chain polyimine and city. The gas permeability (Permeability) and selectivity of the polyimide. It can be found from Table 4 that the order of gas permeability is CO ₂ >H ₂ >O ₂ >N ₂ , mainly because of the basic nitrogen atom in the polyimine molecule, which is preferable for highly polar gases such as carbon dioxide. The affinity of carbon dioxide, the highest penetration rate of carbon dioxide. For non-polar gases such as nitrogen, oxygen and hydrogen, it is mainly related to the size of the molecules. From the results, the values are 29.42, 6.10 and 0.95 barrer.

Compared to the commercially available general polyimine Kapton (RPI-1), CPI- 3 has better permeability and selectivity; compared with the commercially available asymmetric backbone polyimine, Matrimid, the selectivity is comparable, while CPI still shows better permeability, representing that the product is suitable for gas separation.

The present invention discloses a five-carbon ring side chain-containing polyimine and a preparation method thereof, and a dicyclopentadiene (DCPD) is used as a starting material to prepare a diamine having a five-carbon ring. After the diamine and various dianhydrides are polymerized into polyimine, a side chain ring is formed to form a polymer of Intrinsic Microporosity-Polyimides (PIM-PIs), compared to the general poly The quinone imine has excellent gas permeability and selectivity, making it more widely used in future applications.

The above-described embodiments are merely illustrative of the features and effects of the present invention and are not intended to limit the scope of the technical scope of the present invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention should be as set forth in the scope of the claims described below.

Claims (2)

A gas separation membrane prepared by a polyimine having a five-carbon ring side chain having a structure of the formula (I); Wherein, the Ar system is selected from , and One of the group consisting of; n is a positive integer of 70-140; wherein the preparation step of the five-carbon ring side chain-containing polyimine of formula (I) comprises: as in formula (A) The diamine compound is reacted with a mono-anhydride monomer and subjected to thermal ring closure to obtain the pentacyclic ring-containing polyimine of the formula (I); the five-carbon ring of the formula (A) Amine compound: Among them, the compound of the formula (A) is obtained by reacting dicyclopentadiene as a raw material. The gas separation membrane of claim 1, wherein the gas separation membrane is separated by a gas of carbon dioxide, oxygen, nitrogen or hydrogen.